Shock absorber



Oct. 13, 1931. s. wlLBuR 1,826,972

SHOCK ABSORBER Filed May 5, 1927 4 Sheets-Sheet 1 Oct. 13, 1931. L. s. wlLBuR SHOCK ABSORBER Filed may 5, 192'/ 4 Sheets-Sheet 3 Oct. 13, 1931.

L. S. WILBUR sHocK ABsoBBER Filed May 5, 1927 4 Sheets-Sheet 4 VIII/4 www??? latented ct. 173, 1931 Miren STATES PATENT ,LAWRENCE s'. ywriiiarm, or c EvANs'roN, ILLINOIS sirocx Anson-Brin A'ppiieation inea May 5, 192'?. f serial No. 189,130.

My invention relates to a shock absorber more particularly to shock absorber or cushioningA device adapted to be used in the Y device of theY yabove indicated character, y which is adapted to absorb the shocks given to the reaclrrod by means of thefvalveand l 1K5 valve mechanism'7 and to prevent such shocks from being transmitted along said reach rod te the power reverse gear or to the operator ot the quadrant lever. Anotherobject of my invention is to provide a deviceiofthe above indicated character of an improved vconstruction comprising a movable cylinder, having a pistony positioned and normally held in the center thereof, and means for resiliently-retaining said piston inthe center 25 of said cylinder ior holding the pistonrod and 'the valve gear mechanism secured thereto, in a definite position;l guide members on the side of said locomotive along which said I cylinder is adapted. to be reciprocated, and 30 an indicating devicefor showing when the nissen is in the center of the cylinder-,and new s for adjusting the resilient means lfor holding said piston in the center of saidfcylinder. y Y t 35 My invention will be best understood -by reference to thel accompanying-drawings Jfirming a part of this specification7` and in,V which, t l

Figure ,l is a top plan view of ashock absorber incorporating my invention'` and Figure 2 is a sectional view taken onapproximately `the line 2-2 of Figurel. Figure 3 is -a cross-sectional view taken on substantial-y ly the line 3-3 of Figure l and Figure'lis a resssectional view taken on substantially the line la-lofFiO'ure l. Figure-l is a fraginental sectional view taken ony substantially the line 5 -5c`of Figurel, and'Figurev 6 kisa cross-sectional view taken on substantially 50 the line 6-6 of Figure ll. 4Figure 7 c is-a perspective view of a cushioning device employed in my inventionk Figure Sis an elevational view of a modifieation of my invention and Figure 9 isa sectional view takenv online 9 9 of Figure 55 V8. Figure l()k is an elevational sectional View .of other modifications of my invention. Figure ll is a sectional view taken on line 'llll of Figure 10 and Figure .l2 is a sectional view taken on line 1%12 of '60 `Figure 10.

ln the drawings and lfor the purposeofillus- Ytration l have shown the preierredembodivment of myinveifition7 in `which 10 represents the boiler plate on the side of a locomotive,` -6 5 and having arms l1 and lQseeuredfthereto i by bolts` 13 and le, respectively. Said arms havel guide members l5 and lvsecured in opposing relationto each other -by means of suitable bolts -17 and 18', respectively. A170 cylinder 19 is provided-with slots or guideways 2O and 21,-in which said guide members are adapted to fit, and said cylinder may be reciprocated'along'said guide members by jineans of the rearward end-22 of the usual f 7,5 vlocomotive reach rod. Said member 22 is suitably secured to a removable head member'23, which is normally secured in position on the rearward end of said cylinder 19 by means of a plurality of bolts 24 posi tioned;g 0, varound the circumference thereof andV passing through the flange 245. The forward portion 25ct' said Alocomotive reach rodpasses through a. packingnut 267V a vpacking 27 and an opening 28 in the end ofthe removable 35 i cylinder head 29, and into ythe cylinderlll) to a-piston 30. Y

The removable cylinder head 29 is normally secured to a flange 31 of said cylinder 19 by means of a plurality; of-bolts 32 positioned-Q0 Varound thecircumference thereof. The por- -tion 25 ofthe vreachrod is providedwitha -boss having aflange 34 thereon for engaging a disc 35,01 rubber or other similarly resilient material, whichis positioned in one/95 end oi" the piston 30, and the member 25 passes through said disc 35-and is tapered to llit within a tapered opening 3T in said piston.

The smaller end ofthe tapered portion 38 Y of said member 25 has screw thread engage-00 nient with a nut 40. Said nut 40 engages a washer 89, which engages a disc member 35 as shown in Figure 7, and by means of the nut 40 the flange 34 on the boss 33 and the washer 89, the piston 30 is securely held in position on the rearward end of said portion 25 of the reach rod.

Coil spring members 4l and 42 are positioned betwee the piston and the cylinder heads 29 and 28, respectively, for resiliently urging said piston toward the center of said cylinder. 'lhevinner end of coil spring 4l engages plate 48 and is normally secured in gositi`r n thereon by a lug member 44. The other-'end of said spring 4l engages a plate 45, which may be adjusted relative to the cylinder head 29 by means of set screws 4G havinglock nuts 47 thereon. ln a like manner the spring 42 engages a plate 48 and is normally secured thereto by lugs 49. The other end of said spring 42 engages a plate 50, which is adapted to be adjusted relative to the cylinder head 23 by means of set screws 5l, having loclr nuts 52 positioned thereon. `Chain members 53 and 54 are secured to plates 43 and 48 by means of lug members and respectively, and said chain members are provided with adjusting means 57, having loch nuts 58 thereon for the purpose of limiting the inward movement of the springs 4l and 42.

Coiled around the portion 25 of the reach rod within the cylinder l9 is provided an auxiliary spring 59, which has one end secured to the plate 45 by means of an eye member 60 integral with said plate. rlhe other end of said spring 59 is adapted to fit over said boss 33, and when the piston moves sutliciently toward the cylinder head 29, the end of spring 59 engages the flange 84 on said boss. Similarly a coil spring 6l engages and is secured to the plate 50 by means of an eye member 62 integral with said plate. rlhe other end of said spring 6l passes around the nut 40 and is adapted to engage the washer 39 when the piston 30 moves suffiw ciently in the direction toward the cylinder head 28. Since the discs 35 are positioned between the plates 48 and 48, it is obvious that the pressure of the springs 4l and 42 is evenly distributed over said cushioning members,y

which eliminates noise which would other wise result in chattering of the metallic plates against the piston 30. I

ylhe piston 8O is provided with suitable piston rings 58, which prevent a sudden rush of air by said piston but permit air to gradually leali by the same for equalizing the air pres sure, which may be created on both sides of the piston. Through the piston 30 is provided van air duct 64, which has for its purpose to allow air pressure within said cylinder to gradually equalize on both sides of said piston. A tube 65, which normally supplies air pressure through an opening k66 'to `said Vmoves the portion 25 of the reach rod.

cylinder, is secured to the same byy screw thread engagement in an opening 67. @n the forward cylinder head 29 is secured an indicator 68 by means of a set screw 69. Said indicator is provided with a point 70, which is positioned directly above a crease 71 in the portion 25 of said reach rod when the piston is in exactly the center of the cylinder i9, and `the purpose of said indicator is to aid in adjusting theA tension of the springs within said cylinder `in order that the piston will be urged to the center of the cylinder Whenever it has been displaced therefrom. ln ythe normal operation of my invention the portion 22 of the reach rod of the locomotive is moved forward or backward for positioning the valves of the locomotive, and my invention is simply a novel rshoclr absorbing means included within the length of said rod, and when the portion 22 is moved in one direction it positions the cylinder at some point along the guide members l5 and 16 yand it remains in that position until again moved by the operation of said portion lWhen the cylinder is moved, the springs 4l and 42, which 'engage the piston 8l), cause the piston tomovfe along with the cylinder and, thereby, n if ior any reason a shock or a jerk is received by the portion 25 of said rod it is transmitted to the piston 30, which is suddenly forced one way or the lother in said cylinder, but when it moves toward the spring 42 it is restrained by said spring, and at the saine time the chain 53 prevents the spring 4l from ei:- erting an;7 force upon the piston. Therefore, the spring 42, having no opposition quickly returns the piston to the center of the cylinder, and in case the shoclr is very severe the piston be forced endwise far enough to enga-ge the end of spring (3l, which is of very rigid construction, and prevents excess've motion of lthe piston. ln case the piston is pulled forwardly toward spring 4l the action is obviously the `crac-t reverse, and the ten- -dency at 'all ytimes is to keep the piston 30 directly in the center of the cylinder 19. ln addi-'tion to the vspring action l have provided the pipe 65, through which air under pressure may be'forced into the cylinder, and said air will leal; bythe piston rings 63 and into bothends of said cylinder, thereby, affording an increased cushioning means for the piston. Thedeviee as a whole when in operation prevents Vthe creeping of the port-ion 25 of the reach rod, and in addition to this function, it allows certain temporary restrained movement of said portion 25 and thereby protects mechanism secured thereto, from excessive nstrain and at the same time absorbs all shock received `by said portion 25, and protects meehanismwhich may -'be positioned along the rearward `portion 22 of said rod.

"in Figures 8 and 9 is shown a modification of my invention, which consists of substanyll O "Tio with.

Leaders tially the same elements inthe 'same relation to each other, With certain variations, 1n that no cylinder is used inFigures 8 and 9 and the heads 29 are securedto channel members'75 by means of bolts 76 through flanges 77 on the sides thereof at each end of said channel members. The channel members 75 are pro'- vided with guideways 20, as hereinbefore described, and the guide members 15 are adapted to fit in and reciprocate therein. In this modification of my invention a. crosshead 78 is employed in the place ofthe piston 30, and said cross head is provided With ears 79 which act as guide members for preventing the crosshead from being forced out of position. Adjacent theends of the channel members 75 are reinforcing side flanges 80 integral there- The same springs and chains are used in this form of my invention andthe operation is substantially that described hereinbefore y'ith the exception that compressed air is not employed as an auxiliary cushioning means since the interior ofthe mechanism as shown in Figures 8 and 9, is open to the atmosphere.

In `Figures 10,11, and 12,is shown another modification of my invention with certain variations from that disclosed in Figures 1 to 7 inclusive, as follows; the same type of cylinder 19 is employed and having the same cylinder heads 23 and 29. The cylinder is provided with the guideways 20 adapted to reciprocate on the guide members 15 as previously described, butin this form of my invention the usual coil springs have been omi-tder 19 in order that they may be adjusted into Contact with the floating pistons 83 and 84 respectively, in case the air pressure supply, by Which this form of my invention is normally operated, should fail.

An air supply pipe 85 leads from a suitable air pressure reservoir, not shown, to the check valve 86 of any'usual type, Which causes the air pressure in the cylinder 19 to be of a re-V duced vpressure from that supplied in the pipe 85. Pipes 87 and 88 lead to the ends of the cylinder 19 and thereby permit free communication from the valve 86 `to both ends of the cylinder and from the free come munication of air pressure from one end of the cylinder 19 to the other end, and it is therefore obvious thatthe air pressure in both ends of cylinder 19 is at'all times equal. On the end of the portion 25 of the reach rod is secured a thin one-piece piston 89 by means of the nut 80. Said piston 89 is adapted to receive 'cushioning` members 35 in both sides thereof and the floating pistons 83 and 84 areadapted to engage said members 85 for preventing noise and eliminating vibration.

Stop members 91 are positioned in openings 92 through the sides of said cylinder 19 and are held in placeby suitable bolts' 93.

sides of the cylinder 19.

"in any satisfactory manner. vpiston 83 is provided With a cup A98, and the 'same means for holding it in place land in which pass through flanges 94 on said stop members and have sc revvl thread engagement in openings 95 provided in the' thickened portion 96 on the sides of the cylinder 19, pro'- vided for thatv purpose.

The floating pistons 83 and 84 are normally held in contact with said cushioning 'member by means of fluid pressure Within the cylinder 19. The floating piston 84 is-provided With a raised portion 97 for passing over the nut 90 in order that said piston may be complete and air tight across its diameter, and in order to make a substantially air tight fit in the cylinder 19, said fioating piston`84 is provided With a cup 98 having its inner edge held in place by a ring member 99, Which is clamped down upon the inner edge of said cup 98, by means of suitable bolts 100. Within the cup 98 is positioned an expansion ring 101, Which is provided With a sheath 102 of metal having a flangevvvhich is broken at various intervals, as at 103, in order that said flange may be pressed outwardly against said cup member 98 for holding the same into substantially fluidv tight relationship With the The floating piston 83 isprovided With an opening104 through which the portion 25 is permitted to pass and this construction necessitates the use of packing lmaterial 105 which is heldin place by the cover' plate 106 The 'floating operative relation With the sides of cylinder 19, as hereinbefore described for piston 84.Y

The operation of this form of my invention is substantiallythe same as described for'the other forms of my invention, With Y the exception that the springs 81 and 82 have no normaly operating function, but vare to be used'as emergency springs only, andthe pistons 83 and 84 are consistentlyurged to the inward limit of their pistons into contact y `of the cylinder'and it in turn moves the forward portion 25 of the reach rod tothe position desired. Vhen for any reason, the pory tion 25 is suddenly forced out of position, in

either direction, thefloating pistons 83 and 84 operating upon the piston 89 immediately return said piston to the center of the cylinl der and thereby prevent creeping of the portion 25 and accomplish the rsame purpose as explained in the operation of ythe form of my invention described in Figures 1 to 7 lnclusive.

In this connection it should be noted that I have provided a duct 107 `through one of the 'stop members 91vfortlj1ev130 elo purpose .of permitting'air to pass into or 'out of the space between the two floating pistonsj and thereby prevent air pressure building up within said space, which would obvioush7 impede the operation of this device.

While have described my invention in its preferred form, it is obvious that it is capable of variations without departing from the spirit of my invention. l do not therefore desire to be limited to the precise details of construction described and illustrated but desire to avail myself of such variations and modifications as come Within the scope of the appended claims.

I claim as my invention:

1. A. shock absorbing device for a locomotive reach rod; said rod having a front portion and a rear portion; a slidably mounted cylinder provided with two cylinder heads; one of said cylinder heads secured to one of said portions and movable therewith; a piston slidably mounted in said cylinder and secured to the other of said portions; resilient means disposed on each side of said piston between said piston and said cylinder heads; and means connected to said cylinder heads for confining the amplitude of movement of said resilient means.

2. A shock absorbing device for a locomotive reach rod; said rod having a front portion and a rear portion; a cylinder having two cylinder heads; one of said cylinder heads secured for movement with one of said portions; the other of said portionspassing Athrough the other said cylinder head and secured to a piston within said cylinder; and shock absorbing means interposed between said piston and said cylinder heads; said shock absorbing means comprising a plurality of pairs of concentrically positioned coil springs, one of said pairs of concentrically positioned springs being more resistant to compression than the other of said pair of cencentrically positioned springs and means for limiting the range of action for said springs; said cylinder mounted for reciprocatory movement relative to said locomotive.

3. A shock absorbing device comprising a cylinder having two heads removably secured thereto; said cylinder having guideways in the sides thereof; guide members rigidly secured to a locomotive and positioned in said guideways for permi ting reciprocatory movement of said cylinder relative to said locomotive; a rear portion of a locomotive reach rod secured to one of said heads for movement therewith; a piston in said cylinder; a front portion of a locomotive reach rod passing through one of said heads and secured from movement with said piston; shock absorbing spring members interposed between said piston and said heads.

l. A shock absorbing device comprising a cylinder having two heads lremovably secured thereto; said cylinder having guideways in the sides thereof; guide members rigidly secured to a locomotive and positioned in said guideways for permitting reciprocatory movement of said cylinder relative to said locomotive; a rear portion of a locomotive reach rod secured to one of said heads for movement therewith; a piston in said cylinder; a front portion of a locomotive reach rod passing through one of said heads and secured from movement with said piston; shock absorbing spring members interposed between said piston and said heads and means including chains connected to said heads and said shock absorbing spring members for limiting the range of action of said shock absorbing members.

5. A shock absorbing device for a locomotive reach rod; said rod having a front portion and a rear portion; a cylinder having cylinder heads removably secured to the ends thereof; apiston slidably mounted in said cylinder; said rear portion secared for 1novement with one of said cylinder heads; said front portion passing through the other said cylinder' head and being secured for movement with said piston; coil springs interposed between said piston and said cylinder heads; plates interposed between said coil springs and said cylinder heads; and means for varying the force exerted by said springs against said piston. y

6. A shock absorbing device for a locomotive reach rod; said rod having a front portion and a rear portion; a cylinder having cylinder heads removably secured to the ends thereof; a piston slidably mount-ed in said cylinder; said rear portion secured for movement with one of said cylinder heads; said front portion passing through the other said cylinder head and being secured for movement with said piston; coil springs interposed between said piston and said cylinder heads; plates interposed between said coil springs and said cylinder heads; and means for varying the force exerted by said springs against said piston; adjustable means for limiting the extension of said coil springs.

7. A shock absorbing device for a locomotive reach rod; said rod having a front portion and a rear portion; a cylinder having cylinder heads removably secured to the the ends thereof; a piston slidably mounted in said cylinder; said rear portion secured for movement with one` of said cylinder heads; said front portion passing through the other said cylinder head and secured for movement with said piston; coil springs interposed between said piston and said cylinder heads; resilient disc members seated in the faces of said piston, and plate members engaging said springs and said resilient disc members.

8. A shock absorbing device for a locomotive reach rod; said rod having: a front vpor-A tion and a rear portion; a cylinder having cylinder heads removably secured totheends thereof; a piston slidably mounted in said cylinder; said `rear portion secured yfor movement with one of said cylinder heads; said front' portion passing through the other-said cylinder head and secured for movement with said piston; coil springsinterposed between said piston',` and 'said' l'cylinder heads; resilient disc 'members seated in the faces of Vsaid piston,Av and plate` membersl engaging said springs and said resilient disc members; chains adjustably secured to said platefmembers ,for limiting the extension ofV said springs.

9. A shock absorbing device for a. locomotive reach rod; said rodhaving a front portion and a rear portion; acylinder having cylinder" heads removably secured to the ends thereof; a piston slidably mounted in said cylinder; said rear vportion secured for movement with one of said cylinder heads; said front portion passing through the other said cylinder head and secured for movement with said piston; vcoil springs interposed between said piston and said cylinder heads; resilient disc members seated in the faces lof saidfpistomfand plate members engaging said springs andsaid resilient disc members; chains fadjus'tably secured tofsaid plate members for limitingthe extension of said springs; platesinterposed between said y coil `springs and said cylinder heads; and

means forl adjusting the posit-ion? of each of said plates for varying the force exerted by said springs against said pist-on. l

10. A shock absorbing devicefor a locomotive reach rod; said rod having affront portion andv a rear portion; a cylinder'having cylinder heads removably secured to the ends thereof; a piston slidably mounted'in said cylinder; said rear portion secured for movement with one 'of said cylinder heads; said front portion passing through the other-said cylinder headand secured/for reciprocatory movement with said piston; spring means interposed between said piston and said cylinder f heads; plates interposedl between said spring means and said cylinder heads; means for adjusting the position lof each of said plates; resilient discmembers seated in the faces of said piston and plate members engaging said spring means and 'resilient disc members; chains each havingy one end secured to said plate members'and the v other end adjustably' securedto kone L"of said` cylinder heads, for vlimiting the extension :of said springmeans. `f

ll. lA shock absorbing device for a locomothereof; a pistonslidably mounted in said cylinder; said rear portion secured'for movement with one of said cylinder heads; said front portion passing through the other said cylinder (head andv secured for reciprocatory justably secured to one of said cylinder heads, p

for limitinggthe extension of said spring means; vguideways in the sides lof said cylinlo'comotive and positioned in said guideways, for permitting reciprocatory movement of said cylinder .relative to said locomotive.

l2. A shock absorbing device'for a locomotive reach rod; said rod-having a front por'- tion and a rear portion; a cylinder having cylinder `heads removably secured to the ends thereof; a. piston slidablyfmounted' in` 4said cylinder; said rear portion'secured for movement with one Vo'f-said cylinder'heads; said front portion passing through the other said cylinder head and securedfor reciprocatory movementwith'said piston ;.spring means interposed between said piston and saidcylin-V der heads;` plates interposed between said spring means and said cylinder heads; means for adjustingthe position` ofeach of said plates; .resilient Vdisc members seated inthe toV Y der; guide members rigidly secured lto said l faces of said pistonvand' plate members engaging said spring meansand Fresilient disc members; chains each khavingfone end ysecured to saidfplate members and the other end 'adustably secured to one of said cylinder heads, for'limiting the extension .of said spring means;'other spring means within the first said 'spring means; said other spring'means secured'to said adjustable plates. Y 13. A shock absorbing device for a locomotive reach rod; said rod having a front portion and a rear portion; a cylinder having cylinder heads removablysecured to the ends thereof; apiston slidably mounted in'said cylinder ;said rear portion secured for'movement with one of said cylinderheads; said front' portion passing through the othersaid l cylinder head and secured for reciprocatory movement with said piston; spring means in- 'terposed between said piston and said cylinder' heads; platesiinterposed rbetween saidk spring means and said cylinder heads ;means for `adjusting the position ofeach of said plates; resilient disc 'members seated inthe faces of saidpiston and plate members engaging said spring means and resilient disc members chains each'having one end secured to said plate members andthe other end adjustably secured to one ofsaid cylinder heads; for limiting the extension of said spring means;

other spring meanswithin the rst said spring means; said other springs means secured to said adjustable plates; guideways in the sides of said cylinder; guide members rigidly secured to said locomotive and positioned in said guideways, for permitting reciprocatory movement of said cylinder relative to said locomotive.

14. A shock absorbing device for a locomotive reach rod; said rod having a front portion and a rear portion; a cylinder having cylinder heads removably secured to the ends thereof; a piston slidably mounted in said cylinder; said rear portion secured for move'- ment with one of said cylinder heads; said front portion passing throughv the other said cylinder head and secured for reciprocatory movement with said piston; spring means interposed between said piston and said cylinder heads; plates interposed between said spring means and said cylinder heads; means for adjusting the position ot each of said plates; re silient disc members seated in the faces of said piston and plate members engaging said spring means and resilient disc members; chains eachhaving one end secured to said plate members and the other end adjustably secured to one of said cylinder heads, tor limiting the extension of said spring means; means on one of said cylinder heads cao-operating with means on the front portion of said reach rod for indicating` when said piston is in the center of said cylinder.

15. A shock absorbing device for a locomotive reach rod .f said rod having a frontportion and a rear portion; a cylinder having cylinder heads removably secured to the ends thereof; a piston slidably mounted in said cylinder: said rear portion secured for movement with one of said cylinder heads: said front portion passing through the other said cylinder head and secured for reciprocatory movement with said piston; spring means interposed between said piston and said cylinder heads: plates interposed between said spring means and said cylinder heads; means for adjusting the position ot each of said. plates; resilient disc members seated in the faces of said piston and plate members engaging said sprin means and resilient disc members; chains each having one end secured to said plate members and the other end adjustably secured to one of said cylinder hea-ds, for limiting the eXtension ot said spring means; other spring means within the first said spring said other spring means secured to said adjustable plates: 'guideways in the sides ot said cylinder; guide members rigidly secured to said locomotive and positioned in said guideways, for permitting reciprocatory movement of said cylinder relative to said locomotive; other spring` means within the first said spring means for cooperating with the lirst said spring means; piston rings on said piston; an air duct through said piston; and

means for admitting air pressure to said cylinder.

A 16. A shock absorbingV device for a rod divided into two portions; guide members for supporting said device in slidable engagel' ment; a plurality oi' means secured in spaced relation to each other by guideways; said guideways adapted to be reciprocated on said guide members; one of said portions secured for movement with one of said means and the other portion secured to a member; yieldingly held equidistant from both of said means; and means for limiting the movement of said member. i

17. A shock absorbing device 'for a rod divided into two portions; guide members for supporting said' device in slidable engage ment; a plurality of heads secured in spaced relation to each other by guideways adapted to be reciprocated on said guide members; one of said portions secured ior movement with oneyot said heads and the other portion secured to a member yieldingly held equidistant from both of said heads; and means for limiting the movement of said member.

18. A shock absorbing device for a rod divided into two portions; guide members for supporting said device in slidable engagement; a plurality of heads secured in spaced relation to each other by guideways; said ldeways adapted to be reciprocated on said guide members; one ot' said portions secured ior movement with one of said heads and the other portion secured to a member adapted to reciprocate between said heads; shock absorbing means interposed between said member and said heads.

19. A shock absorbing device for a rod divided into two portions; guide members lor supporting` said device in slidable engagement; a plurality otheads secured in spaced relation to each other by guideways; said guideways adapted to be reciprocated on said guide members; one of said portions secured for movement with one ot' said heads and the other portion secured to a member adapted to reciprocate between said heads; shock absorbing means interposed between said member and said heads; means for limiting the range of action of said shock absorbing y means. y

Y 20. A shock absorbing device for a rod divided into two portions; guide members for supporting said device in slidable engagement; a plurality of heads secured in spaced relation to each other by guideways; said guideways adapted to be reciprocated on said guide members; one of said portions secured Y tor movement with one of said heads and the other portion secured to a member adapted to reciprocate between said heads; shock absorbing means interposed between said member and said heads; means for adjusting the torce exerted by said shock absorbing means.

21. A shock absorbing device for a rod dipas lill) vided into two portions; guide members for supporting said device in slidable enga-gement; a plurality of heads secured in spaced relation to each other guideways; said guideways adapted to be reciprocated on said guide members; one of said portions secured for movement with one of said heads and the other portion secured to amember adapted to* reciprocate between said heads; shock absorbing means interposed between said member and said heads; means for indicating when said member is equidistant 'from said heads.

22. A shock absorbing device for a rod divided into two portions; guide members for supportingsaid device in slidable engagement; a plurality of heads secured in spaced relation to each other by guideways; said guideways adapted to be reciprocated 'on said guide members; one of said portions secured for movement with one of said heads and the other portion secured to a member adapted to reciprocate between said heads; shock absorbing means interposed between said heads and said member; means for adjusting the force exerted by said shock absorbing means; and means for limiting the range of action of said shock absorbing means.

28. A shock absorbing device for a rod divided into two portions; guide members for supporting said device in slidable engagement; a plurality of heads secured in spaced relation to each other by guideways; said guideways adapted to be reciprocated on said guide members; one of said portions secured for movement with one of said heads and the other portion secured to a member adapted to reciprocate between said heads; shock absorbing means interposed between said members and said heads; means for limiting the range of action of said shock absorbing means; and means for indicating when said member is equidistant from said heads.

In testimony whereof I have signed my name to this specification.

LAWRENCE S. WILBUR. 

